1. Field of the Invention
The present invention relates to dust collecting mechanism for a groove machining head collecting dust produced when performing groove machining on a thin film, such as when manufacturing thin film solar cells or other devices, and to a groove machining apparatus.
2. Discussion of the Related Art
A manufacturing process for an integrated solar cell includes steps of stacking semiconductor thin films on a substrate and repeating patterning multiple time as described in, for example, Japanese Unexamined Patent Publication JPA2005-191167. This manufacturing process includes forming a metallic lower electrode layer on the brittle material substrate, and as a patterning P1, cutting and dividing the electrode layer into rectangles using a laser beam. Then, forming a P-type light absorption layer and a buffer layer on the patterned electrode layer gives an integrated semiconductor thin film. After that, as a patterning P2, mechanically scribing parts of the stack of the buffer layer and the P-type light absorption layer along lines slightly displaced from grooves formed as the patterning P1 is cut and divided into rectangles. Then a transparent conductive film made of metal oxide on the buffer layer is formed. Subsequently, as a patterning P3, mechanically scribing parts of the stack of the transparent conductive film, the buffer layer, and the P-type light absorption layer along lines slightly displaced from grooves formed as the patterning P2 is cut and divided into rectangles. The thin film solar cell is manufactured in this manner. For this purpose, it is necessary to slightly displace the lines formed as each of the patterning P2 and P3 from the lines formed as the patterning P1, and it is also necessary to form one hundred and several tens parallel grooves at pitches of, for example, approximately 5 mm in one substrate.
Japanese Unexamined Patent Publications JPA2011-155151 and JPA2010-245255 disclose a scribing apparatus for solar cells. The scribing apparatus disclosed in JPA2011-155151 includes, on a base for a scribing head, a tool holder adapted to hold a machining tool, an air cylinder adapted to move the tool holder up and down, a spring adapted to cancel out the weight of the tool holder, and the like, and presses the tool against a workpiece while adjusting a load using the air cylinder. Also, JPA2010-245255 discloses the scribing apparatus that simultaneously performs scribing in multiple positions by attaching a number of heads to a sliding mechanism on a beam.
Japanese Unexamined Patent Publication JPA-Hei9-285939 proposes a dust collecting device that provides a tool head with a dust collector having a fan in order to eliminate swarf from a machine tool.
As Japanese Unexamined Patent Publications JPA2005-191167, JPA2011-155151, and JPA2010-245255 disclose, scribing along patterning lines with a scriber produces dust. In the process of the scribing, once the dust attaches to a thin film solar cell substrate, there arises a problem of the difficulty to remove the dust, or even in the case of successfully removing the dust, damaging the surface of the substrate. Further, although the dust collecting device in JPA-Hei9-285939 has a suction head adapted to suck dust around a rotary tool, rotating the fan gives arise to a problem of complicated structure.